opiates and opioids Flashcards
what is an opiate?
natural narcotic opioid found in the opium poppy (papaver somniferum)
what is an opioid?
any natural or synthetic compound or endogenous peptides that exert biological effects at the opioid receptor
what are the 3 major psychoactive opiates
major- morphine, codeine, thebaine
what are the three pharmacological use of natural opiates and which one is known to be the most potent and effective pain reliever
analgesic, antitussive, and decreased gastric motility
analgesic
what does antitussive and decreased gastric motility do
antitussive-> cough suppressant, in which codeine has decreased the analgesic effect but retains antitussive effects
decreased gastric motility-> can be used to treat diarrhea esp pathogenic
-> Loperamide is an opioid derivative that does not penetrate the BBB and is used to treat diarrhea
what is an example of semi-synthetic opioid, what was the trade name that it was under and what was it used for
diacetylmorphine
heroin
cough suppressant, analgesic, and cure for morphine addiction
what are the administration routes for natural opiates
oral- morphine readily absorbed through GI but high variability, codeine has more consistent oral absorption
Subcutaneous, IM, IV- more stable systematic levels and IM is the preferred routes for morphine in clinical setting and IV is common for recreational use
inhalation- historic route of (recreational) administration for raw opium is smoking
what are the administration routes for semi-synthetic opioid?
oral- heroin administration by oral route produces the same potency and efficacy as morphine
IV- dramatically more potent and rapid than morphine due to increased lipophilic structure (increased BBB permeability)
inhalation or intranasal-> occasional route for recreational use
Fill in the blank: Development of numerous semi-synthetic opioids followed the isolation of ________ and _______ and subsequent discovery of the structures
morphine and codeine
TRUE OR FALSE: freebase heroin can be smoked while other preparations can be finely ground and snorted
true
at what doses do opioids exert limited psychoactive effects
5-10mg morphine
what are 5 therapeutic effects of opioids?
pain relief, drowsiness, constriction of pupils, decreased sensitivity to external or internal stimuli, dream-filled sleep
for more, look at slide 10
what are two subjective effects of high doses of opioids
-euphoria or elation ( in contrast to relaxed state at lower doses)
- rush-> most pronounced by IV (rapid, intense state of euphoria, described by others as a “whole body orgasm”)
what are three physiological effects of high doses?
pinprick pupils, nausea and vomiting ( opioids can act at the chemoreceptor trigger zone in the area postrema to induce the vomit reflex) and moderate respiratory depression
Fill in the blank: Prescription opioids (________) are one of the fastest growing classes of drugs of abuse
oxycontin
TRUE OR FALSE: tolerance to opioids develops slowly and tolerance to respiratory and euphoric effects develops more slowly than tolerance to analgesic effects
false: quickly and rapidly
what are the 3 types of tolerance?
metabolic-> some increase in drug metabolism
behavioural-> highly relevant in addicts
pharmacodynamic-> principle mechanism of tolerance– decreased expression of opioid receptors
what is the reason why there are somewhat exaggerated perceptions of opioid withdrawal
cinematic creative license
True or false: opioid withdrawals are much more severe than withdrawal from barbiturates or alcohol
false; much less severe, since severe alcohol withdrawal can be fatal
opioids never fatal
what two things is withdrawal heavily influenced by
drug tolerance and dependence (check slide 15 for extra information and graph)
what is rebound hyperactivity?
withdrawal produces neurochemical and behavioural changes that are often opposite to the effects of intoxication
when do stages of withdrawal begin
6-12 hours after last administration, peaks 26-27hours persists less than 1 week
what can be seen in the first stage of withdrawal
- Restlessness and agitation is first sign
- Excess yawning, agitation, violence
- Chills, hot flashes, shortness of breath
- Intense piloerection (goosebumps) – origin of the term ‘cold turkey’
- Increasing drowsiness and deep sleep (often 8-12 hours)
what can be seen in the second stage of withdrawal
- Cramps in stomach, back, legs
- Vomiting, diarrhea, profuse sweating
- Twitching of the extremities – shaking of hands and kicking of legs – origin of the term ‘kicking the habit’
- Symptoms become progressively less severe until gradually disappearing
